A Concise Enantioselective Synthesis of (-)-Ranirestat

A concise, enantioselective synthesis of the potent aldose reductase inhibitor ranirestat (1) is reported. The synthesis was accomplished employing Inexpensive, commercially available starting materials. A palladium-catalyzed asymmetric allylic alkylation (Pd-AAA) of malonate 4 was utilized as a key transformation to construct the tetrasubstituted chiral center in the target.